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Huichao Shi, Xiao Huang, Tao Meng, Huaiming Shen, Zhiming Yang
Research on error compensation method of multi-channel ultrasonic flowmeter based on SVM

The measurement process of multi-channel ultrasonic flowmeter is affected by the distribution of flow field in the pipeline, which makes the measurement results of sound channel have large errors, and finally leads to large errors in the integration results of flow. Especially when the ultrasonic flowmeter is installed near the rear of the valve, elbow and other spoiler, the influence of the flow field distribution in the pipeline on the measurement results of the ultrasonic flowmeter is difficult to avoid. Aiming at the distribution of the flow field in the pipeline behind the gate valve and its influence on the multi-channel ultrasonic flowmeter, this paper studies the influence of the opening of the gate valve, the distance between the ultrasonic flowmeter and the gate valve and the installation angle of the gate valve on the measurement error of the multi-channel ultrasonic flowmeter through CFD simulation experiments, and puts forward the error compensation model of the multi-channel ultrasonic flowmeter based on SVM, The measurement results of multi-channel ultrasonic flowmeter caused by the flow field distribution behind the gate valve are compensated, and the compensation results are compared with the flow integration results. It is found that the compensation model based on SVM proposed in this paper has better compensation effect.

Song chaofan, Wu yan, Liu zhe, Hao min
Application of integrity management method to improve the management level of gas flow standard facility

To improve the quality control performance on quantity transfer made by gas standard facility, the integrity managementconcept is applied to the quality control of quantity transfer in this study, and a "four-step method" is proposed. Herein,the application of calibrating a critical flow Venturi nozzle(CFN) with the mt gas standard facility is shown as anexample. By applying the four-step method, it is possible to accurately identify the key influencing factors and quantitatively analyze their influence on the measurement results, conduct risk assessment and risk prediction for themeasurement deviation of key measuring instruments and standard facility, and improve the quality control of standard management from passive disposal to active prediction, monitoring and control, so as to realize systematic, refined andintelligent management of standard quantity transfer.

Mengna Li, Chengze Lv, Wenli Li, Chunhui Li
In-use Measurement of Ultrasonic Flowmeter based on Machine Learning

To guarantee the accuracy of ultrasonic flowmeter, an in-use measurement system for ultrasonic flowmeter incorporating digital signal processors and machine learning approaches was proposed. Experimental analysis has been carried out to determine the variables affecting the accuracy of ultrasonic flowmeter. Based on random forest algorithm, we evaluated the contribution of different variables on the accuracy performance of ultrasonic flowmeter, and establish a model including variables extraction and prediction of flow deviationfor in-use measurement of ultrasonic flowmeter. By obtaining data of the flowmeter signal index, flow rate characteristics, sound velocity and flow velocity etc., the flow deviation of ultrasonic flow meter is predicted using random forest algorithm, and the difference between predicated value and observed value is smaller than 0.76 %. Furthermore, the degree of influence of different variables on the accuracy of ultrasonic flowmeter was analysed. The uncertainty of the prediction result was evaluated, with an extended uncertainty U = 0.92 % ~ 0.22 % (k = 2).

Bo Wu, Yong Wan, Bibo Qian, Tao Meng
Research on Technology Status and Development Direction of Large Diameter Water Flow Standard Facility in China

The performance of large diameter water flow facility will have a direct impact on the accuracy and value uniformity of detected flowmeter measurement results. In addition, ensuring the stability and reliability of facility performance has always been a key link in the traceability and transmission of value of large water flow. However, the application scale and measurement capability of existing large diameter facilities are difficult to fully meet social needs. In this paper, based on National Institute of Metrology (China), provincial metrology institutes and related flow enterprises, focusing on the domestic typical large diameter water flow standard facility has been built to carry out the investigation and research, comparative analysis of different types of device structure principle, measuring ability, technical characteristics and the regional distribution, etc. Based on this, the key technologies that may emerge in the field of large diameter water facility in the future are explored and the future development trend is summarized. The relevant research results of this paper have important practical significance for improving the measuring capacity of domestic large water flow facilities, standardizing and improving the construction of traceability system for large water flow measurement.

Liu xun, Luo Caiping , Liu Renhuai
Research on intelligent ultrasonic gas meter based on Lora communication technology

The existing membrane gas meter has the disadvantages of low measurement accuracy and difficult to realize remote monitoring. The new ultrasonic gas meter can solve these problems after adopting the new Lora communication technology. This paper describes the measurement principle of the ultrasonic gas meter and the components of the ultrasonic gas meter. The hardware composition block diagram of the gas meter and the design idea of low power consumption are described. The software design framework and main design flow chart of the gas meter are described. The detailed design of segment code liquid crystal is described. The design of Lora communication module is also described in detail. The flow measurement accuracy of the gas meter in the flow range of 0.16 m³ / H ~ 6 m³ / h and the temperature adaptive flow measurement accuracy in the temperature range of - 10 °C ~ + 40 °C meet the measurement accuracy requirements of national standards, In the actual application scenario, the communication distance and communication performance of the gas meter also meet the requirements of customers. In the actual application scenario, the communication distance and communication performance of the gas meter also meet the requirements of customers. The gas meter has been used in many gas companies for a long time and in large quantities, and the results meet the use requirements. Finally, the conclusion is given and it is pointed out that the gas has reached our expected goal.

M. D. Schakel, F. Gugole, D. Standiford, J. Kutin, G. Bobovnik, N. Mole, R. Maury, D. Schumann, R. Kramer, C. Guenz , H.-B. Böckler, O. Büker
Establish traceability for liquefied hydrogen flow measurements

The EU aims to be climate-neutral by 2050 and usage of liquid hydrogen (LH2) for transportation is expected to grow fast. With the expected uptake, traceability in custody transfer is required. Existing metrological infrastructure can be used to provide traceability with basic calibrations performed typically under ambient conditions. However, due to the very challenging LH2 process conditions, with temperatures as low as 20 K, there is a need to determine the flow measurement uncertainty at these process conditions. Within the Joint Research Project (JRP) 20IND11 “Metrology infrastructure for high-pressure gas and liquified hydrogen flows” (MetHyInfra) [1], traceability for liquefied hydrogen flow measurements is developed by a three-pronged approach: (I) assessment of transferability of water and LNG calibrations to LH2 conditions; (II) cryogenic Laser Doppler Velocimetry (LDV) adapted to LH2 flow applications; (III) assessment of transferability of water, liquefied nitrogen, and liquefied helium calibrations in the vaporisation method to LH2 conditions. In this paper the initial MetHyInfra project results are presented comprising: (I) description of LH2 flow meters, water and LNG calibration results, analytical model prediction statements of uncertainty at LH2 conditions when calibration is performed under ambient conditions, finite element numerical modelling analysis of various thermal effects affecting CFMs at LH2 conditions, (II) design modifications of cryogenic LDV to ensure operability at LH2 conditions, (III) description of the vaporisation standard. It was found that obtaining a definite quantitative number of liquefied hydrogen flow measurement uncertainty from the analytical model is challenging for a variety of reasons.

H. M. Moțit, P. Mate
Developments by a new flow measurement structure based on reaction force. Extended reaction flowmeters

There are presented the developments ensured by a new worldwide flow measurement structure, based on the reaction force, "the extended reaction flowmeter" ,elaborated by the first author, the subject matter of the patent application filed with European Patent Office EP 21020546, together other reaction flowmeters without moving parts.Initially are synthetically reitered the constructive and structural specificities of "the extended reaction flowmeters" (shortly "ERF").Then, starting from the facilities offered by the specific structural scheme of the ERF, significant simplified compared to that of the known compound flowmeters, are presented the developments offered by the using of this new flow measurement structure based on reaction force, by describing the improuved results achieved by two constructive variants of ERF, regarding the binomial of the two essential features (turndown and accuracy, interrelated of the flowmeters, by achieving a large extension of the turndown to very important values, correlated with an optimal range of the accuracy values.

Hu Wenqing, Xu Zhipeng, Zhang Gaoming, Guo Jing
Investigation of the pVTt Gas Flow Standard with Active Thermal Compensation

pVTt has been employed as the primary gas flow standard in many countries due to its unique advantages like high accuracy, simple structure, low maintenance, etc. However, its calibration efficiency is relatively low because of the long stabilization time of intake and outtake procedures. To reduce the stabilization time, a novel pVTt gas flow standard with active thermal compensation was proposed. Above all, structure andprinciple of the new pVTt standard device was introduced. Subsequently, the numerical simulation was performed to investigate the influence of thermal compensation. Finally, experiments were carried out, and results showed that the stabilization time after intake completion could be reduced from ten minutes to one minute, which means calibration efficiency was improved a great deal.

K. F. Zhang, S. Zhang, B. Gao, W. H. Zhou, L. S. Yang
Study on the relationship between the size change and the measured flow value of the Parshall flumes open channel weir tank flowmeter

At present, as an important measuring instrument for measuring sewage discharge, the principle of open channel flowmeter is the functional relationship between liquid level and flow. By measuring the liquid level of water flow in the tank, and then according to the flow value of the relationship between liquid level and flow in the corresponding Parshall flume, therefore, the accuracy of Parshall flume size is closely related to its measurement accuracy. In this paper, we introduce a kind of adjustable size of Parshall flume. Through experiments, we find out the relationship between the flow rate and the standard flow rate under different sizes, and then use the method of multiple regression to fit the correction equation.

Xuejing Li, Xinhong Yao, Yuan Jin, Haiyang Li
A Numerical Study on the Influence of Temperature on the Measurement Performance of Lead-bismuth Electromagnetic-flowmeter

Liquid lead-bismuth eutectic (LBE) is one of the preferred materials for accelerator driven subcritical(ADS) transmutation targets and coolants in fourth-generation nuclear reactors. Due to the complex and interacting physical and chemical factors in the measurement process of LBE in high temperature operating environment, it is very difficult to control the flow and on-line calibration, resulting in the slow development of LBE flow meter technology, which hinders the fourth Generation nuclear reactor technology development. Electromagnetic flowmeter is currently recognized as one of the most suitable LBE flow measuring instruments in the world. In this paper, the measurement characteristics of LBE electromagnetic flowmeter at high temperature are numerically analyzed and studied, the influence of temperature on magnetic field strength and flow field distribution is quantitatively given, and the measurement linearity of LBE electromagnetic flowmeter is analyzed. The research conclusions provide a certain reference for the detection of lead-bismuth alloy flow parameters and the on-line calibration of LBE electromagnetic flowmeters in the nuclear industry control process.

Page 10 of 912 Results 91 - 100 of 9113